Protective garments worn by fire fighters are designed to perform several functions. Of these, protection from heat and flame are perhaps the most important characteristics of the garments. In addition to providing protection from heat and flame, the garments, however, should be as light as possible, should provide some breathability and should encumber the wearer as little as possible.
Conventional fire fighter garments are generally constructed having a number of discrete layers. Typically, these layers include an outer shell, a moisture barrier layer, a thermal barrier layer, and an inner lining. The layers are generally made from appropriate thermally-resistant materials to provide protection against heat and flame.
In the past, one difficulty that has been encountered in designing protective garments to be worn by fire fighters is to prevent the garments from absorbing and retaining moisture. For instance, protective garments worn by fire fighters usually become wet during use due to external exposure to extinguishing water or rain. Also, fire fighter garments can become wet due to the absorption of perspiration given off by the wearer. Unfortunately, when the protective garment absorbs moisture, the characteristics and properties of the garment can be adversely affected. For example, when retaining moisture, the protective garment can become significantly heavier.
Besides increasing in weight, the presence of moisture within a protective garment also adversely affects the thermal properties of the garment making the garment less effective in shielding its wearer from thermal heat. In particular, since water is a much better heat conductor than air, the rate of heat transfer through the garment increases. Also, it has been discovered that as water heats up in a protective garment, the water can turn to steam under exposure to heat and actually burn a person wearing the garment.
Ultimately, when protective garments as described above become wet or soaked with water or other fluids, the garments become hot and uncomfortable to work in due to the increased weight and due to the increased rate of heat transfer through the garment. As a consequence, a wearer can only spend a limited amount of time working or performing tasks in the garment due to the possibility of heat stress.
In the past, in order to prevent water from being absorbed by protective garments worn by firemen, the garments have been treated with a water resistant composition. The water resistant treatments applied to conventionally made protective garments, however, have not proven to be durable and have been found to become ineffective after the garment has been placed in use for a period of time. In particular, it has been discovered that conventionally applied water resistant treatments become significantly degraded when the protective garment is washed. Specifically, it has been found that the water resistant treatments begin to degrade only after five (5) laundry cycles and typically lose most of their effectiveness after ten (10) laundry cycles.
As such, a need currently exists for an improved water resistant fabric and protective garment to be worn by fire fighters. More particularly, a need exists for a method of applying a water resistant treatment to a protective garment that will not degrade over a period of time and that can withstand normal laundering.